1. Field of the Invention
The present invention relates to a compensating amplifier, and more particularly to a compensating amplifier which reduces the influence of interference waves in an AM/FM automobile antenna.
2. Prior Art
In automobile antennas for receiving AM/FM waves, the most widely used antennas have a length which causes FM waves to be in a constant condition, which is 0.8 m to 1.0 m.
When an antenna of this length is used in a regular passenger car, the top of the antenna reaches much higher than the automobile body. Because of this, the antenna sometime hits the garage ceiling, etc. and is damaged. Accordingly, an antenna which is shorter than the conventional antenna and is free from the above problems is more desirable.
However, when the antenna is shortened in length by half, the resonant frequency of the antenna becomes the same as high frequency bands (170 MHz-222 MHz) of television signals. Thus, the antenna's sensitivity within this frequency becomes greater. In addition, since the output of television transmissions is often very strong, the high channel signals of the television signal disturb FM signal reception.